Azo dye.



UNITED STATES PATENT FFIUE.

OSCAR DRESSEL AND ANTON OSSENBECK, OF ELBERFELD, GERMANY, ASSIGNORS TOFARBENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD, GERMANY, ACORPORATION OF GERMANY.

AZO DYE.

Specification of Letters Patent.

Patented Feb. e, 1907 To all whom it may concern.-

Be it known that we, OsoAR'DREssEL and ANTON OSSENBECK, citizens of theGerman Empire, residing at Elberfeld, Germany, Kingdom of Prussia, haveinvented new and useful Improvements in Azo Dyes, of which the followinis a specification.

We have dyestufis are obtained by combinin the diazo compounds ofnon-sulfonate nitroortho-amino henolic compounds with 2-arylamino-5-napthol-7-sulfonic acids.

The new dyestuffs are in the shape of their alkaline salts dark powderssoluble in water and dyeing wool from acid-baths generally from red toviolet shades, which on chroming change to from blue to black fastshades. By reduction of the new dyestufis with stannous chlorid andhydrochloric acid non-sulfonated diaminophenolic compounds and2-arylamino-5-naphthol-6-amino 7 sulfonic acids are obtained. u

In carrying out the new process practically we can proceed as follows,the parts being by weight: 15.4 arts of 4-nitro-2-aminophenol arediazotize in the usual manner by means of hydrochloric acid and sevenparts of sodium nitrite. The diazo compound precipitated during thediazotization is filtered off, stirred u with water to a thin paste, andadded with stirring to a solution of thirtytwo parts of2-phenylamino-5naphthol-7- sulfonic acid mixed with an excess of sodiumcarbonate. The dyestuff is filtered oil,

pressed, and dried. It is, after being dried and pulverized, in theshape of it's sodium salt a dark powder soluble in water with a violetcolor and in concentrated sulfuric acid with a violet color. Byreduction with stannous chlorid and hydrochloric acid 2-4-diaminophenoland 2-phenylamino-5-na hthol- 6-amino-7-sulfonic acid is obtaine The newdyestufi dyes wool from acid-baths Bordeaux shades, which are changed toblueblack when chromed after dyeing.

- The p'rocess is carried out in an analo ous manner on using otherdiazo compounds of non-sulfonated nitro ortho aminophenolic com ounds orother 2-arylamino-5-naphthol- 7-su fonic acids.

und that new and valuable azo In the following table the properties ofsome of the new dyestuffs are given:

Having now described our invention and:

Dyes wool D yes wool when Dyestuft obtained fromfrom acid chrom'ed after5 5 bathedyeing- 1. -nitro-S-aminophenoL Bordeaux. Blue-black.

2. 5-nitro-2-amiinophenoL 21m enyhmflg Bordeaux. Greenlsh blue. 3 ri-r ricramic t o -sutonic mm Bordeaux. Blue.

4. (Lnitrc-Q-ami- HOAQVSOL Bordeaux. Blue.

5. 4-nitro-2-nminophenoL a r a t 0 Yb Bordeaux. Blue-black. 6 5

' a m l no-5- 6 4 a c i l r I i -n ro- -amz- -su omc noarcresoh acid.Bordeaux. Violet-black.

7. 5-nitro-2-aminophenoL 0 h0g1? Bordeaux. Greenish blue.

sylaminoa 6 t a iii i 'i i -!1l IO'rflmlo -su no-4-cresol. Conic acid.Bordeaux Blue in what manner the same is to be performed,

what we claim as new, and desire to secure by Letters Patent, is

1. The hereindescri obtainable by combining diazo com ounds ofnon-sulfonated nitro-ortho-amino enolic compounds with 2-arylamino-5-napthol-7- sulfonic acids, which dyestuffs are, after being dried andpulverized, in the sha e of their alkaline salts dark owders solu le inwater; yielding u on re uction with stannous chlorid and lYdIOOlllOIlOacid; diaminophenolic compounds and 2-arylar'nino-5-naphthol-6-amin0-7-sulfonic acids and dyeing wool from acid-bathsgenerally from red to violet shades, which on chrommg change to fromblue to black, substantially as hereinbefore described.

2. The herein-described new azo dyestuffs, which can be obtained bycombinin diazotized 4-nitro-2-amino henol with 2-penylamino-5-naphtho1-7-si1 fonic acid,which dyestuff is, after beingdried and pulverized, in the shape of its sodium salt a dark powdersoluble in water with a violet color and in concentrated sulfuric acidwith a violet bed new azo dyestuifs color; yielding upon reduction withstannous In testimony whereof we have hereunto chlorid and hydrochloricacid Q- L-diami set our hands inthe presence of two sub- 10 nophenol and2-phenylamin0-5-naphthol-6- scribing witnesses. a111in0-7-sulf0nic acid;and dyeing wool from OSCAR DRESSEL. acid-baths Bordeaux shades, whichare ANTON OSSENBECK. changed tc blue-black when chromed after Witnesses:

dyeing, substantially as hereinbefore de- OTTO KGNIG,

scribed. J. A. RITTERSHAUS.

